mx31_3ds: revert 3ds debug board relate code

Because we add a 3ds debug board support in mxc level, we remove
those redundant codes from board level.

Signed-off-by: Jason Wang <jason77.wang@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx3/Kconfig b/arch/arm/mach-mx3/Kconfig
index a11112a..e063657e 100644
--- a/arch/arm/mach-mx3/Kconfig
+++ b/arch/arm/mach-mx3/Kconfig
@@ -67,6 +67,7 @@
 config MACH_MX31_3DS
 	bool "Support MX31PDK (3DS)"
 	select ARCH_MX31
+	select MXC_DEBUG_BOARD
 	select IMX_HAVE_PLATFORM_IMX_UART
 	select IMX_HAVE_PLATFORM_MXC_NAND
 	select IMX_HAVE_PLATFORM_SPI_IMX